The present invention relates to a method for granulating active ingredients for use in oral compositions, including chewing gum. More particularly, the present invention relates to a granulation which includes polyvinyl acetate, alcohol, and a modified cellulosic.
Extensive efforts have been undertaken to control and sustain release of active ingredients in oral compositions, particularly chewing gum. Many active ingredients are not stable in the presence of excess moisture, temperature, and various chemicals. Certain sweeteners, especially aspartame, are water-soluble and readily degradable. Aspartame tends to be readily degraded by flavors, particularly aldehyde flavors. Active ingredients also tend to have initial bursts of flavor or sweetness.
Various methods have been investigated to control the release of active ingredients. Fluid bed coating, fiber spinning, and spray drying are methods known in the art. These methods are designed to coat and protect the ingredient so there is prolonged release of sweetener or flavor as opposed to an overpowering initial release. Another method involves granulating or agglomerating ingredients into a granular matrix which also provides for a more controlled release of ingredient.
Another method for controlling release involves encapsulation of active ingredients. Encapsulation methods utilizing polyvinyl acetate ("PVAc") with a plasticizer are useful for protecting sweeteners in chewing gum. Encapsulation with PVAc is effective because PVAc is not water soluble and is not readily degradable. Furthermore, PVAc is a food-safe ingredient. This method, however, is very costly and requires expensive machinery and skilled labor.